松潘县磨子沟泥石流发育特征及危险区范围预测研究

发布时间：2018-05-12 11:38

本文选题：磨子沟泥石流 + 危险区范围　；参考：《西南交通大学》2017年硕士论文

【摘要】：泥石流是常见的山区地质灾害之一,泥石流暴发时携带大量的砂石,是一种固、液两相流体。由于泥石流暴发突然、历时短暂,严重威胁着人们正常的生产、生活及生命财产安全。我国山区居民大多居住在地势相对平坦的泥石流堆积区上,这就为泥石流灾害的形成埋下了隐患。近年来,在我国山地较为集中的西部地区相继发生了众多泥石流灾害,2008年汶川地震之后,在汶川、北川、绵竹以及都江堰等地地质灾害频发,尤其在雨季,泥石流灾害发生频繁。早期,通过统计学和建立数学模型等方法均可以对泥石流危险区范围进行预测,但是由于统计学和数学模拟所产生的分析误差较大,导致对泥石流危险区范围的预测结果与实际存在较大的差别,从而无法对泥石流防治提出有效的指导建议。近年来计算机技术不断提高,国内外的学者越来越多使用计算机模拟的方式计算和分析泥石流危险区范围,数值模拟方法可以对泥石流的初期形成、发育流动、堆积区漫流等各个阶段进行更加准确和形象的模拟分析,进而为泥石流的防治工作提供有效并切合实际的建议。本文基于对磨子沟泥石流流域现场的勘查和当地居民的调查访问,详细了解当地的气象条件、地质概况等,根据以上调查结果,分析磨子沟泥石流形成条件和发育特征。计算泥石流的容重、流速、流量等运动特征和动力学参数。利用AutoCAD、Surfer、ANSYSAPDL软件提取磨子沟泥石流的高程数据点,并建立泥石流堆积区的三维实体模型,利用CFX模拟20年一遇磨子沟泥石流的全过程,分析泥石流的三维流场和危险区范围。最后根据以上计算和分析结果,对磨子沟泥石流的综合治理提供了有效准确的指导建议。得到的主要结论如下:(1)研究泥石流流域的地质环境背景,并分析了导致泥石流形成的地形地貌条件、松散物源条件以及水源条件。采用"雨洪修正法",计算得到了磨子沟泥石流的各项动力学参数。(2)建立磨子沟泥石流沟口及堆积区的三维实体模型,使用CFX模拟分析该泥石流流动的全过程,并对其危险区范围进行预测,得到与实际较一致的危险区范围。(3)针对磨子沟泥石流暴发的情况,提出"拦砂坝+防护堤"相结合的治理方案。
[Abstract]:Debris flow is one of the common geological disasters in mountainous area. Debris flow carries a large amount of sand and gravel when it breaks out. It is a solid and liquid two phase fluid. Because of the sudden and short-lived debris flow, people's normal production, life and property safety are seriously threatened. Most of the people living in mountainous areas in China live in relatively flat debris flow accumulation areas, which buries hidden dangers for the formation of debris flow disasters. In recent years, a large number of debris flow disasters have occurred in the western region, where the mountainous regions of China are relatively concentrated. After the Wenchuan earthquake in 2008, geological disasters occurred frequently in Wenchuan, Beichuan, Mianzhu and Dujiangyan, especially in the rainy season. Debris flow disasters occur frequently. In the early stage, the range of debris flow risk area could be predicted by statistics and mathematical model, but the error of analysis caused by statistics and mathematical simulation was large. As a result, there is a big difference between the prediction result of debris flow risk area and the actual situation, so it is impossible to put forward effective guidance suggestions for debris flow prevention and control. In recent years, with the development of computer technology, more and more scholars at home and abroad use the method of computer simulation to calculate and analyze the range of debris flow risk area. Numerical simulation method can be used to form and develop the flow of debris flow in the initial stage. In order to provide effective and practical suggestions for debris flow prevention and control, more accurate and vivid simulation analysis is carried out in various stages of accumulation area. Based on the site survey and local residents' investigation in Mozigou debris flow basin, the local meteorological conditions and geological conditions are studied in detail in this paper. Based on the above investigation results, the formation conditions and developmental characteristics of the debris flow in Mozigou are analyzed. The movement characteristics and dynamic parameters of debris flow, such as bulk density, velocity and discharge, were calculated. The elevation data points of debris flow in Mozi gully are extracted by AutoCAD Surfern ANSYSAPDL software, and the three-dimensional solid model of debris flow accumulation area is established. The whole process of debris flow in Mozi ditch is simulated by CFX, and the three-dimensional flow field and dangerous area range of debris flow are analyzed. Finally, according to the above calculation and analysis results, it provides effective and accurate guidance for the comprehensive treatment of debris flow in Mozi gully. The main conclusions are as follows: (1) the geological environment background of debris flow basin is studied, and the topographic and geomorphological conditions, loose source conditions and water source conditions of debris flow formation are analyzed. By using "rain flood correction method", the dynamic parameters of debris flow in Mozigou are calculated. The three-dimensional solid model of debris flow mouth and accumulation area in Mozi ditch is established, and the whole process of debris flow is simulated and analyzed by CFX. The range of the dangerous area is predicted, and the range of dangerous area in accordance with the actual situation is obtained. According to the situation of debris flow in Mozigou, the combined treatment scheme of "sand bar and dam protection against embankment" is put forward in view of the occurrence of debris flow in Mozi gully.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.23

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